Baiting of bacteria with hyphae of common soil fungi revealed a diverse group of potentially mycophagous secondary consumers in the rhizosphere

TY - JOUR

T1 - Baiting of bacteria with hyphae of common soil fungi revealed a diverse group of potentially mycophagous secondary consumers in the rhizosphere

AU - Rudnick, M.B.

AU - van Veen, J.A.

AU - de Boer, W.

N1 - 5863, ME embargo AM= 24 mnd; Data Archiving: data archived at publisher

PY - 2015

Y1 - 2015

N2 - Abstract Fungi and bacteria are primary consumers of plant-derived organic compounds and therefore considered as basal members of soil food webs. Trophic interactions among these microorganisms could, however, induce shifts in food web energy flows. Given increasing evidence for a prominent role of saprotrophic fungi as primary consumers of root-derived carbon, we propose that fungus-derived carbon may be an important resource for rhizosphere bacteria. To test this assumption, two common saprotrophic, rhizosphere-inhabiting fungi, Trichoderma harzianum and Mucor hiemalis, were confronted in a microcosm system with bacterial communities extracted from the rhizospheres of a grass and sedge species, Carex arenaria and Festuca rubra. This showed a widespread ability of rhizosphere bacteria to attach to and feed on living hyphae of saprotrophic fungi. The identity of the fungi had a strong effect on the composition of these potentially mycophagous bacteria, whereas plant species identity was less important. Based on our results, we suggest that food web models should account for bacterial secondary consumption since this has important consequences for carbon fluxes with more carbon dioxide released by microbes and less microbial carbon available for the soil animal food web.

AB - Abstract Fungi and bacteria are primary consumers of plant-derived organic compounds and therefore considered as basal members of soil food webs. Trophic interactions among these microorganisms could, however, induce shifts in food web energy flows. Given increasing evidence for a prominent role of saprotrophic fungi as primary consumers of root-derived carbon, we propose that fungus-derived carbon may be an important resource for rhizosphere bacteria. To test this assumption, two common saprotrophic, rhizosphere-inhabiting fungi, Trichoderma harzianum and Mucor hiemalis, were confronted in a microcosm system with bacterial communities extracted from the rhizospheres of a grass and sedge species, Carex arenaria and Festuca rubra. This showed a widespread ability of rhizosphere bacteria to attach to and feed on living hyphae of saprotrophic fungi. The identity of the fungi had a strong effect on the composition of these potentially mycophagous bacteria, whereas plant species identity was less important. Based on our results, we suggest that food web models should account for bacterial secondary consumption since this has important consequences for carbon fluxes with more carbon dioxide released by microbes and less microbial carbon available for the soil animal food web.

KW - Fungal-bacterial interactions

KW - Mycophagy

KW - Trophic interactions

KW - Mycorrhizosphere

KW - Root exudates

KW - Fungal inhibition

KW - Fungal suppression

KW - Rhizosphere

KW - NIOO

U2 - 10.1016/j.soilbio.2015.04.015

DO - 10.1016/j.soilbio.2015.04.015

M3 - Article

SN - 0038-0717

VL - 88

SP - 73

EP - 82

JO - Soil Biology & Biochemistry

JF - Soil Biology & Biochemistry

IS - September

ER -